THE EFFECT OF CALIFORNIA WEATHER CONDITIONS ON PRICE PREMIA FOR ORGANICALLY GROWN VEGETABLES IN THE UNITED STATES

Organic vegetable producers typically earn a premium over conventional producers to cover the added costs of organic production. The premium can vary greatly, making organic vegetable farming riskier than conventional farming and causing potential financial problems for new organic farming enterprises. Further, organic vegetable production is geographically concentrated in California, and the variation in organic price premia depends upon regional production factors, especially weather conditions. This study examines the relationship between organic vegetable price premia and California weather conditions near organic vegetable farms. Analysis is based on a unique data set of daily prices from the Boston Terminal Wholesale Market and California weather data from the National Climate Data Center.Demand and Price Analysis,

The effect of functional roles on group efficiency

The usefulness of ‘roles’ as a pedagogical approach to support small group performance can be often read, however, their effect is rarely empirically assessed. Roles promote cohesion and responsibility and decrease so-called ‘process losses’ caused by coordination demands. In addition, roles can increase awareness of intra-group interaction. In this article, the effect of functional roles on group performance, efficiency and collaboration during computer-supported collaborative learning (CSCL) was investigated with questionnaires and quantitative content analysis of e-mail communication. A comparison of thirty-three questionnaire observations, distributed over ten groups in two research conditions: role (n = 5, N = 14) and non-role (n = 5, N = 19), revealed no main effect for performance (grade). A latent variable was interpreted as ‘perceived group efficiency’ (PGE). Multilevel modelling (MLM) yielded a positive marginal effect of PGE. Groups in the role condition appear to be more aware of their efficiency, compared to groups in the ‘non-role’ condition, regardless whether the group performs well or poor. Content analysis reveals that students in the role condition contribute more ‘task content’ focussed statements. This is, however, not as hypothesised due to the premise that roles decrease coordination and thus increase content focused statements; in fact, roles appear to stimulate coordination and simultaneously the amount of ‘task content’ focussed statements increases

Designing fuzzy rule based classifier using self-organizing feature map for analysis of multispectral satellite images

We propose a novel scheme for designing fuzzy rule based classifier. An SOFM based method is used for generating a set of prototypes which is used to generate a set of fuzzy rules. Each rule represents a region in the feature space that we call the context of the rule. The rules are tuned with respect to their context. We justified that the reasoning scheme may be different in different context leading to context sensitive inferencing. To realize context sensitive inferencing we used a softmin operator with a tunable parameter. The proposed scheme is tested on several multispectral satellite image data sets and the performance is found to be much better than the results reported in the literature.Comment: 23 pages, 7 figure

Elevated arousal at time of decision-making is not the arbiter of risk avoidance in chickens

The somatic marker hypothesis proposes that humans recall previously experienced physiological responses to aid decision-making under uncertainty. However, little is known about the mechanisms used by non-human animals to integrate risk perception with predicted gains and losses. We monitored the behaviour and physiology of chickens when the choice between a high-gain (large food quantity), high-risk (1 in 4 probability of receiving an air-puff) option (HGRAP) or a low-gain (small food quantity), no-risk (of an air-puff) (LGNAP) option. We assessed when arousal increased by considering different stages of the decision-making process (baseline, viewing, anticipation, reward periods) and investigated whether autonomic responses influenced choice outcome both immediately and in the subsequent trial. Chickens were faster to choose and their heart-rate significantly increased between the viewing and anticipation (post-decision, pre-outcome) periods when selecting the HGRAP option. This suggests that they responded physiologically to the impending risk. Additionally, arousal was greater following a HGRAP choice that resulted in an air-puff, but this did not deter chickens from subsequently choosing HGRAP. In contrast to human studies, we did not find evidence that somatic markers were activated during the viewing period, suggesting that arousal is not a good measure of avoidance in non-human animals

Glycosylated proteins preserved over millennia: N-glycan analysis of Tyrolean Iceman, Scythian Princess and Warrior.

An improved understanding of glycosylation will provide new insights into many biological processes. In the analysis of oligosaccharides from biological samples, a strict regime is typically followed to ensure sample integrity. However, the fate of glycans that have been exposed to environmental conditions over millennia has not yet been investigated. This is also true for understanding the evolution of the glycosylation machinery in humans as well as in any other biological systems. In this study, we examined the glycosylation of tissue samples derived from four mummies which have been naturally preserved: - the 5,300 year old "Iceman called Oetzi", found in the Tyrolean Alps; the 2,400 year old "Scythian warrior" and "Scythian Princess", found in the Altai Mountains; and a 4 year old apartment mummy, found in Vienna/Austria. The number of N-glycans that were identified varied both with the age and the preservation status of the mummies. More glycan structures were discovered in the contemporary sample, as expected, however it is significant that glycan still exists in the ancient tissue samples. This discovery clearly shows that glycans persist for thousands of years, and these samples provide a vital insight into ancient glycosylation, offering us a window into the distant past

Inhibition of Tendon Cell Proliferation and Matrix Glycosaminoglycan Synthesis by Non-Steroidal Anti-Inflammatory Drugs in vitro

The purpose of this study was to investigate the effects of some commonly used non-steroidal anti-inflammatory drugs (NSAIDs) on human tendon. Explants of human digital flexor and patella tendons were cultured in medium containing pharmacological concentrations of NSAIDs. Cell proliferation was measured by incorporation of 3H-thymidine and glycosaminoglycan synthesis was measured by incorporation of 35S-Sulphate. Diclofenac and aceclofenac had no significant effect either on tendon cell proliferation or glycosaminoglycan synthesis. Indomethacin and naproxen inhibited cell proliferation in patella tendons and inhibited glycosaminoglycan synthesis in both digital flexor and patella tendons. If applicable to the in vivo situation, these NSAIDs should be used with caution in the treatment of pain after tendon injury and surgery

Postdischarge assessment after a heart failure hospitalization: the next step forward.

Heart failure (HF) is the most frequent cause of hospitalization for patients >65 years of age. Mortality during the initial hospitalization ranges from 6% to 7% in Europe to 3% to 4% in the United States, depending on the length of hospital stay. Poor outcomes have universally been shown after discharge, with 60- to 90-day mortality rates of 5% to 15% and hospital readmission rates of 30%. Whereas the prognosis of patients with chronic HF has improved in recent years, there has been no change in the high risk of death or rehospitalization after an HF hospitalization. In addition to the lack of new therapies, incomplete relief from fluid overload, insufficient patient education, lack of implementation of evidence-based therapies, and poor postdischarge follow-up planning are among the main causes of these poor outcomes. A better assessment of the patient at the time of discharge and in the following weeks seems therefore as mandatory. This article outlines the main components of such a program. These include the personnel who should be involved, i.e. HF specialists and cardiologists versus non-specialists, the variables which should be assessed, i.e. those related with congestion and fluid overload, the times when they should be assessed, as the phase at highest risk is immediately after discharge from hospital, and, finally, the aims of such programs. We retain that an improvement of post-discharge follow-up will be able to significantly improve patients’ outcomes with a rate of success comparable, if not greater, to that which can be achieved by new therapies

Modularization of multi-qubit controlled phase gate and its NMR implementation

Quantum circuit network is a set of circuits that implements a certain computation task. Being at the center of the quantum circuit network, the multi-qubit controlled phase shift is one of the most important quantum gates. In this paper, we apply the method of modular structuring in classical computer architecture to quantum computer and give a recursive realization of the multi-qubit phase gate. This realization of the controlled phase shift gate is convenient in realizing certain quantum algorithms. We have experimentally implemented this modularized multi-qubit controlled phase gate in a three qubit nuclear magnetic resonance quantum system. The network is demonstrated experimentally using line selective pulses in nuclear magnetic resonance technique. The procedure has the advantage of being simple and easy to implement.Comment: to appear in Journal of Optics B: Quantum and Semiclassical Optic

Area Regge Calculus and Discontinuous Metrics

Taking the triangle areas as independent variables in the theory of Regge calculus can lead to ambiguities in the edge lengths, which can be interpreted as discontinuities in the metric. We construct solutions to area Regge calculus using a triangulated lattice and find that on a spacelike hypersurface no such discontinuity can arise. On a null hypersurface however, we can have such a situation and the resulting metric can be interpreted as a so-called refractive wave.Comment: 18 pages, 1 figur